How to Know Your Hair Porosity and Why

Hair porosity is the defining factor of how much moisture your hair can hold and retain. It is an important factor for determining hair health as it lets you know how well hair products such as oils pass through the outermost layer of your hair, also known as the cuticle.

Know Your Hair Porosity

Here are some methods to determine your hair porosity.

1. Float test

The easiest way to test your hair porosity is via the float test. To perform this test: (1)

1. Properly wash your hair with a shampoo like you always do, and then dry your hair thoroughly.
2. Take a glass filled with water.
3. Drop a strand of your hair in the water and observe if it sinks or floats.
   • If the strand floats and then sinks, you’re likely to have low-porosity hair.
   • If the strand floats in the middle then you have medium-porosity hair.
   • If the strand sinks quickly, then you have high-porosity hair.

2. Characteristics features

Characteristics of low-porosity hair: (1)

• Hair products don’t get absorbed easily by your hair and accumulate on the surface.
• Your hair takes a long time to dry or wet.
• When washing your hair, you need more water to saturate the hair.
• Chemical treatments are less effective.

Characteristics of medium-porosity hair: (1)

• Your hair is very easy to style.
• Your hairstyle stays in place for a long time.
• Your hair has a healthy and shiny appearance.
• Your hair dries quickly.

Characteristics of high-porosity hair: (2)(3)

• Water gets absorbed quickly into your hair.
• Your hair breaks easily.
• Chemical treatments and hair products exert their effects quickly.
• Textured, wavy, curly, or coily hair is more likely to be porous than straight hair.

3. Spray test

The extent of water absorption by hair is the defining factor for deciding your hair porosity. Spray water on your hair and observe how quickly your hair absorbs the water. High-porosity hair absorbs water faster than low-porosity hair.

For reference, hair can absorb 75% of the maximum quantity of water within 4 minutes. (4)

4. Tests performed by professionals

There are other ways of testing porosity but you can’t perform these on your own. These are performed by an expert only and include: (1)

• Dynamic vapor adsorption: This test estimates the weight of your hair after it is exposed to humidity.
• Fiber swelling: This test calculates the measurements of a hair fiber after exposing it to water.
• Gas adsorption: This test exposes a sample of your hair to nitrogen to study the distribution of nitrogen absorbed by the hair and estimate the size of the pores in the cuticle.

Types of Hair Based on Porosity

Hair can be divided into three categories based on its porosity. (1)

1. Low-porosity hair

The characteristic feature of low-porosity hair is that the cuticles are very close together and woven tightly. This makes the hair more resistant to water and chemical treatments.

2. Medium-porosity hair

Medium-porosity hair is considered normal-porosity hair. The defining feature of this hair type is that the cuticles are bound together but less tightly than those in low-porosity hair. This means that your hair will absorb and retain water quite well.

Medium-porosity hair is adequately receptive to bleach, hair color, and other chemical treatments.

3. High-porosity hair

The cuticles are not bound tightly but are widely spaced in high-porosity hair. This can be because the cuticle is compromised due to mechanical or chemical stresses.

Mechanical stress can arise from combing or repeated wetting and drying of hair, while chemical stresses include oxidative colorants and ultraviolet radiation. (5)

Why Is It Important to Know Your Hair Porosity?

To have healthy and hydrated hair, hair products should be able to pass to your cortex via your cuticle. If your cuticles are woven tightly together or if you have low-porosity hair, the oil and water will not be able to penetrate the cuticle to reach the cortex that easily. This will make your hair remain dehydrated with low moisture content.

However, having high-porosity hair may not be ideal too. This is because if the cuticles are widely spaced, the hair will have a hard time retaining moisture. (1)(6)

Factors Affecting Hair Porosity

Factors that cause you to have low or high hair porosity include: (7)

• Genetics – If you have a family history of low hair porosity, you may have low hair porosity too.
• Hair damage – Hair products that contain harsh chemicals, blow-drying, bleaching, and heat styling can cause the cuticles of your hair to become open.
• UV exposure – Increased exposure to UV rays can increase your hair porosity. (7)
• Hair treatments – Bleached and chemically treated hair is more porous than natural hair. (6)

Most-Asked Questions About Hair Porosity

What is the best hair ingredient/product for high-porosity hair?

If you have high hair porosity or if your hair is suffering from damage arising from routine washing and the use of harsh shampoos, you may want to start using coconut-based hair oils. These oils work by preventing an increase in hair porosity. (8)

What are some good practices for low-porosity hair?

Low-porosity hair is unable to receive proper hydration, which is why you can use a steamer to open the cuticle via heat and infuse hydration into the hair. There are hand-held steamers that you can use to style your hair.

Another point to note is that if you have low porosity hair, you should not use products that cause buildup such as butter, but use those that are rich in humectants such as glycerin. (6)

Final Word

Hair porosity may be a new term for you but an understanding of it is important to know what steps are necessary to make your hair more manageable and to take good care of them.

If your hair porosity is due to genetics, you may not be able to control it much, but taking good care of your hair can help make them healthy.